diff --git a/dom/animation/AnimationPlayer.cpp b/dom/animation/AnimationPlayer.cpp
index 6ac038b75ab..5e3037247d9 100644
--- a/dom/animation/AnimationPlayer.cpp
+++ b/dom/animation/AnimationPlayer.cpp
@@ -697,6 +697,9 @@ AnimationPlayer::UpdateFinishedState(bool aSeekFlag)
   } else if (!currentFinishedState && mIsPreviousStateFinished) {
     // Clear finished promise. We'll create a new one lazily.
     mFinished = nullptr;
+    if (mEffect->AsTransition()) {
+      mEffect->SetIsFinishedTransition(false);
+    }
   }
   mIsPreviousStateFinished = currentFinishedState;
   // We must recalculate the current time to take account of any mHoldTime
diff --git a/dom/animation/KeyframeEffect.h b/dom/animation/KeyframeEffect.h
index 24f71f12f47..2531b41452b 100644
--- a/dom/animation/KeyframeEffect.h
+++ b/dom/animation/KeyframeEffect.h
@@ -300,10 +300,10 @@ public:
     return mIsFinishedTransition;
   }
 
-  void SetIsFinishedTransition() {
+  void SetIsFinishedTransition(bool aIsFinished) {
     MOZ_ASSERT(AsTransition(),
                "Calling SetIsFinishedTransition but it's not a transition");
-    mIsFinishedTransition = true;
+    mIsFinishedTransition = aIsFinished;
   }
 
   bool IsInPlay(const AnimationPlayer& aPlayer) const;
diff --git a/layout/style/nsTransitionManager.cpp b/layout/style/nsTransitionManager.cpp
index 6061e8e4400..63eaae79e06 100644
--- a/layout/style/nsTransitionManager.cpp
+++ b/layout/style/nsTransitionManager.cpp
@@ -831,7 +831,7 @@ nsTransitionManager::FlushTransitions(FlushFlags aFlags)
             // a non-animation style change that would affect it, we need
             // to know not to start a new transition for the transition
             // from the almost-completed value to the final value.
-            player->GetEffect()->SetIsFinishedTransition();
+            player->GetEffect()->SetIsFinishedTransition(true);
             collection->UpdateAnimationGeneration(mPresContext);
             transitionStartedOrEnded = true;
           } else if ((computedTiming.mPhase ==